After releasing SVG Animation Assistant as a Windows and uploading it to itch.io I posted about it on some forums related to Inkscape. I put the app on "MVP sale" at $2.25 and then waited.
Nothing happened for about a month, then suddenly one day the first purchase came through!
After this I made 8 sales over the subsequent months. Not ramen profitability but certainly a positive signal from the market. People are willing to pay for this thing!